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<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        let arr = [12, 5, 8];

        let res = arr.map(item => item * 2);

        alert(res);
    </script>

    <script>
        let score = [19, 85, 99, 25, 90];

        let res = score.map(item => item >= 60 ? '及格' : '不及格')

        alert(score);
        alert(res);
    </script>
</body>

</html>